SummaryA way to reduce the weight of the compact extruder is to choose a shorter motor. Many of us use nema17 motors that are 48mm tall. There are motors with the same footprint, but 40 or 36mm tall. These motors are usually less powerful, but with some of them you can get away as the full current your electronics can provide will squeeze all the available torque out of the motor (the only drawback is heat). This part is for J-head style hotends (like the new Prusa nozzle MKII) and for thin drive gears (MK7 won't fit). You can use the gears and ilder from this other model http://www.thingiverse.com/thing:100982 Please note these part is for a 30mm distance between support holes in the x-carriage of Prusa i3. A new version for 48mm long motors has been added too. An error fix was done as idler was difficult to fit centered, please use new versions of stl This thing is based on Kliment, Josef Prusa and Shane Graber compact extruders. Please note I created another version of this thing with another type of hotend attachment after I had one filament alignment problem with this one. http://www.thingiverse.com/thing:168365